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206               PRACTICAL ORGANIC CHEMISTRY

bisulphite compound, which after standing for half an hour is
filtered and pressed at the pump and washed with a little water
and spirit. The mass is then ground to a thick paste with water
and true solution of potassium cyanide added. After a short
time mandelic nitrile separates as a reddish oil and is removed
by means of a tap-funnel with the addition of a lit'tle ether.

The ether is allowed to evaporate on the water-bath and th e
nitrile is then hydrolysed by continuing to heat it on the water-
bath with the addition of 4  5 times its volume of cone.
hydrochloric acid until crystals appear on the surface. Water
is added and the hot liquid decanted and filtered from any oil.
On cooling, the crystals are filtered, washed with a little cold
water and dried. A further quantity can be extracted from the
filtrate with ether. It may be recrystallised from benzene,
Yield, 10  15 grms.
C0H6CH(OH)CN + HCl + 2HoO
= C0H6CH(OH).COOH + NH4C1.
Properties.  Colourless needles, m. p. 118-119; dissolves
readily in hot water and in 6 parts of water at 20. The acid is
racemic; the active components exhibit a rotation of [a]fju= :
157 in aqueous solution. See Appendix^ p. 306.
PREPARATION 97.
Phenyl Methyl Carbinol, CGH5 CH(OH).CH3
Grignard, Compt. rend. 1900,  130, 1322 ;   Klages and   Ullen-
dorf, Der., 1898, 31, 1003.
36 grms. methyl iodide.
150 c.c. ether (purified and carefully dried over sodium).
6 grms. magnesium ribbon or powder.
26       benzaldehyde.
The magnesium methyl iodide is first prepared and Is
formed by the action of methyl iodide on the metal. The
magnesium ribbon or powder is placed in a dry, round fin sic